This invention relates to a time divided digital signal transmission system comprising: a transmitter for converting plural analog signals to digital signals, generating multiplexed time divided signals from the digital signals, and transmitting the multiplexed time divided signals by a digital data transmission circuit; and a receiver for receiving the multiplexed time divided signals, demultiplexing the multiplexed time divided signals so as to thereby obtain the original digital signals, and converting the original digital signals back into the analog original signals. This invention relates more particularly to a time divided digital signal transmission system in which the synchronizing signals and clock signals thereof are effectively used for the analog-to-digital conversion and the digital-to-analog conversion.
The time divided digital signal transmission system is a kind of multiplexed digital signal transmission system which converts plural analog signals to digital signals, multiplexes the digital signals to obtain time divided signals, and transmits the time divided signals to a receiver. Generally, a manchester signal coding (phase coding) technique is used for the multiplexed digital signal transmission system. In this system, "1" and "0" of the manchester code are different in phase by 180.degree. so that the DC signal level need not be transmitted, and the fundamental frequency for the digital transmission may be low. However, a synchronous signal (sync signal, hereafter) for demultiplexing the time divided signal must be transmitted together with the manchester code. The sync signal is transmitted by being superimposed on to the transmitted multiplexed digital signals, so that the analog signals can be reproduced synchronously in the receiver. In this way, the sync signal generated in the transmitter is reproduced in the receiver and can be effectively used.